Corrosion-resistant soluble oil composition



United States Patent 3,408,297 CORROSION-RESISTANT SOLUBLE OIL COMPOSITION David B. Sheldahl, Griflith, Ind., assiguor to Sinclair Research, Inc., New York, N.Y., a corporation of Delaware No Drawing. Filed Feb. 28, 1966, Ser. No. 530,317 7 Claims. (Cl. 252-335) This invention relates to novel soluble oil compositions having rust-inhibiting properties. More particularly this invention pertains to novel hydrocarbon based emulsifiable oils exhibiting excellent rust-inhibiting properties as a result of the addition of a combination of corrosion inhibiting materials.

Soluble oils are used as cutting, spraying and rust preventing oils and generally include, besides the base hydrocarbon oil, a small amount of water, an emulsifying agent and a corrosion or rust inhibitor. One important function of cutting fluids is cooling. However, due to the increased use of cast iron and low carbon steels, a cutting fluid which inhibits corrosion of both work material and the tool is necessitated. Emulsifiable cutting oils which are satisfactory for use with alloy steels frequently lack sufficient rust-inhibiting properties for satisfactory use with cast iron and low carbon steels. The fortification of a soluble oil with rust inhibitors is complicated. To be an acceptable additive, a rust inhibitor must demonstrate a solubility and compatibility with the neat soluble oil. Many of the otherwise acceptable rust inhibiting additives cause the product to gel or to separate upon standing. Furthermore, such additives often require addition in high concentration or have a relativley high degree to toxicity.

It is an object of this invention to provide a soluble oil for cutting, spraying and grinding which contains a particularly effective combination of materials to inhibit corrosion and rust. Another object of this invention is to provide a soluble oil for cutting, spraying and grinding containing a particularly effective combination of materials that will not cause product separation or gelation, and may be added in economically desirable concentrations. A further object of this invention is to provide a soluble oil for cutting, spraying and grinding having excellent cooling and lubricating properties. It is a still further object of this invention to provide a non-volatile, toxicologically acceptable, soluble oil for cutting, spraying and grinding that can be used with cast iron or low carbon steels.

According to the invention, these desirable objectives are attained by novel soluble oils, which contain a mineral lubricating oil as the base or major component, one or more emulsifiers and small amounts of each of the following oil-soluble materials A and B:

(A) A fatty amido diamine having the structural formula:

wherein R is an aliphatic hydrocarbon containing at least 6 and preferably 12 to 22 atoms, and R and R are divalent aliphatic hydrocarbon radicals of 2-8 carbon atoms, advantageously 2-4 carbon atoms. The members of this class of diamines are cationic and possess a primary and a secondary amine group in addition to the acyl radical attached to the amido nitrogen. The acyl radical in the above formula may be straight or branched chain, saturated or unsaturated, and, if desired, may contain nondeleterious substituents. The acyl radical is preferably a carboxylic acid residue of a high molecular weight acid, such as oleic, stearic, palmitic, linoleic, ricinoleic, lauric,

and like acids. The R and R groups may also be substituted but preferably are polymethylene groups.

A particularly preferred fatty amido diamine is Diamine 257 which has the general structure described above, wherein R and R are trimethylene and R is a straight chain unsaturated hydrocarbon radical derived from corn oil and having about 16-18 carbon atoms. Diamine 257 is well known in the art, having been described in US. Patent No. 3,024,259 to David D. Sheldahl and Thomas O. Counts, and is characterized by having an acid number of less than 5, an average amine equivalent weight of 210, and one primary and one secondary basic amine group. It has a density of 0.935 at 25 C. and is a viscous liquid or fluid paste.

(B) A substituted imidazoline component having the structural formula:

ar H H wherein R is as defined above in connection with component A.

In order to provide preferred compositions which are especially stable, I include a component C, as designated below.

(C) A sulfo-succinate, often having the structural formula:

wherein R is an aliphatic hydrocarbon of at least 6, preferably of 10-24 carbon atoms. Although R may be unsaturated, it is preferably saturated, and especially an alkylene radical such as the saturated residue of an olefin polymer. It is also preferred that the sulfo group be attached to a carbon atom which is beta to the -COOX group. X in the formula may be a hydrocarbon group, preferably alkyl of up to about 6 carbon atoms or X may be an alkali metal or ammonium, including organic ammonium, ion. The two Xs together may be an alkaline earth metal, or the Xs may be absent to give an anhydride group. In any event the R and X groups are such as to provide an oil-soluble sulfo-succinate. The preparation of the sulfosuccinate compounds of this invention is described in US. Patent 2,028,091 to Jaegers.

In each of the components A, B and C, the R-components are such as to give an agent which is soluble, at least in additive amounts, in the base mineral oil.

The above-mentioned components can be employed in the following approximate concentrations: about 0.25-5 weight percent of the fatty amido diamine; about 0.25-5 weight percent of the sulfo-succinate; about 0.25-6 weight percent of the substituted imidazoline.

Since different metal cutting operations are employed in industry, the exact proportions of the various ingredients of the character described above may vary according to the specific operation in which the soluble oil will be used. Ordinarily, however, the soluble oil will include about 40-95 weight percent mineral lubricating oil base, about 4-20 weight percent of one or more emulsifiers, about 1-5 weight percent of coupling agents, about 1-10 total weight percent of the A, B and C components designated above, and a small amount, for instance, about 1-5 weight percent, of water. Other ingredients, such as bactericides, foam inhibitors, etc., may be present, for example, in amounts of about 1-10 percent by weight.

The oils used as the base and major component in the emulsifiablc oils of the present invention are mineral lubricating oils, The oils used including the petroleum lubricating oils such as refined coastal oils and refined Mid-Continent oils. The oils may be refined by acid treatment, solvent extraction, hydrogenation or other procedures. Although various oils of lubricating viscosity can be used in the products of my invention, I prefer to use a substantially anhydrous lubricating oil with a viscosity from about 50-1200 SUS at 100 F., preferably 50150 SUS at 100 F. I have had my best results with an acid-refined coastal oil with a viscosity of about 100 SUS at 100 F.

To improve the emulsifiability of the various components, I may add a coupling agent. The function of such an agent is to couple the aqueous portion of the neat soluble oil to the continuous oil phase to give a clear product and also to couple the neat oil to diluent water added to provide an emulsified soluble oil suitable for use. Among the well-known coupling agents usable in the composition are the aliphatic ether-alcohol compounds containing from about 1-30 carbon atoms, for instance, diethylene glycol; the ether complexes of ethyl Cellosolves, Carbitol, and butyl Cellosolve; the polyether glycols with terminal ether groups; and the polyoxyalkylene glycols, as well as ethylene glycol, propylene glycol, etc. One or more of the above coupling agents can be used either alone or in mixtures, and in various amounts. Generally about 0.5-5 percent, preferably about 1-3 weight percent are employed.

Various emulsifiers known in the art may be used in the soluble oils of this invention. I prefer to use an oil soluble aromatic sulfonate as, for instance, ammonium, alkali and alkaline earth metal aromatic sulfonates. The

. 4 parts of water, depending upon the particular application contemplated. Thus, where the resulting emulsion is to be used as a lubricant for grinding operations, for example, it has been found that about one part of the oil for each 20-80 parts of water, and particularly one part of the oil to 20'or parts of water, producesvery satisfactory results. For use in quenching operations, emulsions formed with one part of soluble oil per 20-40 parts of water have been found to be very advantageous. As a rolling mill oil, emulsions containing one part of the composition for each 5-20 parts of water effect very desirable results.

The following examples will serve to illustrate the present invention but are not to be considered limiting.

EXAMPLE I 82.35 parts coastal mineral lubricating oil with a viscosity of 100 SUS at 100 F. is charged into a kettle containing 6.0 parts ofsodium mahogany sulfonate (60% sodium mahogany sulfon'ate in lube oil), and the mixture is heated and stirred at a temperature of about l40l50 F. 4.0 parts mixed tall oil and rosin acids and 0.55 part sodium hydroxide dissolved in 2.25 parts water is added followed by 1.2 parts hexylene glycol, 1.0 part of Diamine 257, 1.0 part tetrapropenyl sodium sulfo-succinate and 1.35 parts of tallow imidazoline. The mixture is agitated using an intense mixer for a period of about 30 minutes.

. Several soluble oil compositions, listed in Table I were subjected to a rust test, Rust Test Procdure A, to determine their utility as rust-inhibiting cutting oils. Each of the soluble oil compositons is designed for a different metal cutting operation. None of the oils contained any sulfo-succinate substituted imidazoline or fatty amido diamine. The rust test procedure employed is described below:

Cellosoive Diethylene Glycol Hexylene Glycol Rosin Acids Mixed Tall Oil and Rosin Acids Sodium Hydroxide Potassium Hydroxide...

sulfonates used herein include the salts of synthetic sulfonic acids and petroleum mahogany sulfonic acids; and these may be exemplified by ammonium mahogany sulfonates, calcium dipropylene benzene sulfonate, calcium mahogany petroleum sulfonates, calcium dinonyl naphthalene sulfonate, calcium didodecylbenzene sulfonate, sodium mahogany sulfonates, etc. Other oil-soluble emulsifiers employed may be, for instance, saponified phenols or naphthenic acids, alkali metal, e.g., sodium and potassium, rosin and rosin acid soaps, amine salts of rosin acids, oleates, etc. Emulsifiers of the anionic type and the nonionic type may be used, such as, for examples, liquids or solids selected from the group consisting of alkaryl polyoxyalkylene oxyalkanols, and polyoxyethylene derivatives of hexitol anhydride partial long chain fatty acid esters. In general, about 2-10 percent by weight of emulsifier is usually employed.

Additional optional additives may be used as aforementioned. When using a bactericide, I prefer to incorporate tetrachlorophenol; however, various compatible bactericides can be used. Moreover, they can be used either alone or in combination, for instance, in an amount of about 0.5-1 percent by weight. Other agents in small amounts may be present including, for instance, additional corrosion inhibitors.

In use as soluble oil emulsions the compositions of'this invention are frequently dispersed in about 1-20 or more Rust test procedure A Freshly out, clean, dry cast iron chips are sifted over an mesh screen to remove fines and dust. Approximately 40 grams of the screened 'chips are placed in a clean, dry ml. beaker. A 5 percent soluble-oil emulsion (prepared with ppm. CaCO hard water) is poured over the chips. The chips are agitated for one minute at 5 minute intervals. Five minutes after the third agitation, the beaker is covered with a small watch glass and inverted, allowing the emulsion to drain from the chips. The inverted beaker, chips and watch glass are placed on clean paper towels. The "beaker is drawn to the edge of the watch glass (but retaining the chips inside the beaker) so as to permit continued drainage and the combination is allowed to stand undisturbed for 24 hours. The beaker is removed and the chips are observed for the presence of rust,

None of the soluble-oil compositions in Table I that were tested by the above procedure exhibited any rust preventing properties. The chips were badly rusted and fused together.

The same soluble-oil compositions were again given the identical rust test outlined above after addition singly and in combination of various amounts of Diamine 257, tetrapropenyl sodium sulfo-succinate, and

5 tallow imidazoline. The results are reported in Table II as follows:

TABLE II 0.25 to 5 weight percent of a member selected from the group consisting of the oil-soluble alkali metal, alkaline Additive, Parts by Weight Fatty Amldo Diamine Sulfo-Suecinate Substituted Imidazolin Test Result Fatty Amido Diamine Sulio-Succinate Substituted Imidazoline Test Result Fatty Amido Diamine SulIo-Succinate Substituted Imldazoline Test Result Fatty Amide Diamine... Sulio-Sucoiuate substitusteld Imidaz oline.

. l. 1. 0. 1. 35 Test Result Fatty Amldo Diamine.-. 3. 00 2.00 1. 00 Sulfo-Succinate Substituted Imldazoline- 4. 05 2. 70 1. Test Result 1 No rust. 3 Heavy rust. a Very heavy rust. 4 Trace rust. Medium rust. Light rust.

When added to Oil A, the fatty amido diamine and the imidazoline were effective by themselves, but often caused a separation of the product upon standing, or caused the product to gel. To improve the stability of the composition, the sulfo-succinate was added in combination with the fatty amido diamine and the imidazoline. When all three additives were used in suificient concentrations, excellent corrosion protection was obtained and, moreover, no product separation or gelation occurred. The effectiveness of the combination of the fatty amido diamine and substituted imidazoline as low concentrations is also shown by the data. Also, the combination of inhibitors was very effective in oils B, C, D and E, but the amounts of inhibitors had to be varied.

What is claimed:

1. An emulsifiable oil composition consisting essentially of a mineral oil base as the major component, an emulsifier selected from the group consisting of the sodium and potassium salts of naphthenic acids, oleic acid, rosin acids, tall oil acids and oil-soluble sulfonic acids, about 1-5 weight percent water, about 0.25-5 percent of an oil-soluble fatty amido diamine having the structural formula:

0 H H R ll 1% R-1 IR I'HI wherein R is an aliphatic hydrocarbon containing at least 6 carbon atoms, and R and R are divalent aliphatic hydrocarbons of 2-8 carbon atoms, about 0.25-6 weight percent of an oil-soluble, substituted imidazoline having the structural formula:

H N-l-H H E I I wherein R is a monovalent aliphatic hydrocarbon containing at least 6 carbon atoms, said amounts being sufficient to provide rust inhibiting properties, and about earth metal and ammonium salts of sulfo-succinic acid having the structure:

wherein R is aliphatic hydrocarbon of about 6 to 24 carbon atoms.

2. The composition of claim 1 wherein the emulsifier is an oil-soluble, aromatic sulfonate.

3. The composition of claim 1 wherein is added about 0.5-5 percent by weight of a coupling agent.

4. An emulsifiable oil composition consisting essentially of a mineral lubricating oil base with a viscosity of about 50-100 SUS at F., about 0.5-3.0 weight percent of a coupling agent, about 2-10 weight percent of an aromatic sulfonate emulsifier, about 0.54 weight percent water, about 0.25-5 percent weight of an oilsoluble fatty amido diamine having the structural formula:

o R -'-I IRiIIRzI I--H wherein R is an aliphatic hydrocarbon containing at least 6 carbon atoms, and R and R are divalent aliphatic hydrocarbons of 2-8 carbon atoms, about 0.25-6 weight percent of an oil-soluble, substituted imidazoline having the structural formula:

wherein R is a monovalent aliphatic hydrocarbon containing at least 6 carbon atoms, and about 0.25-5 percent of an oil-soluble sulfo-succinate selected from the group consisting of alkali metal, alkaline earth metal and 7 I ammonium salts of sulfo-succinic acid having the structure:

wherein R is aliphatichydrocarbon of about 6 to 24 carbon atoms, said amounts being suificient to provide rustinhibiting properties.

5. The composition of claim 3 in which the coupling agent is an aliphatic ether-alcohol of up to about 30 carbon atoms.

6. The composition of claim 5 wherein the sulfo-succinate is a sodium salt of sulfo-succinic acid wherein R is tetrapropenyl.

7. The composition of claim 5 wherein the emulsifier is a mixture of an aromatic sulfonate and a salt selected from the group consisting of the sodium and potassium salts of naphthenic acids, oleic acid, rosin acids and tall DANIEL E. WYMAN, Primary Examiner.

20 W. H. CANNON, C. F. DEES, Assistant Examiners;

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,408,297 October 29, 1968 David B. Sheldahl It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 34, "to" should read of Column 2 lines 17 to 24, the formula should appear as shown below:

I? //N-CH RC\ N-CH I I H H Column 3, line 5, "including" should read include Column 4, line 30, "procdure" should read procedure Columns 5 and 6, TABLE II, seventh column, last line thereof, "(2)" should read (3) Column 6, line 51 "50-100 SUS at 150 should read 50-150 SUS at 100 F.

Signed and sealed this 17th day of March 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents 

1. AN EMULSIFIABLE OIL COMPOSITION CONSISTING ESSENTIALLY OF A MINERAL OIL BASE AS THE MAJOR COMPONENT, AN EMULSIFIER SELECTED FROM THE GROUP CONSISTING OF THE SODIUM AND POTASSIUM SALTS OF NAPHTHENIC ACIDS, OLEIC ACID, ROSIN ACIDS, TALL OIL ACIDS AND OIL-SOLUBLE SULFONIC ACIDS, ABOUT 1-5 WEIGHT PERCENT WATER, ABOUT 0.25-5 PERCENT OF AN OIL-SOLUBLE FATTY AMIDO DIAMINE HAVING THE STRUCTURAL FORMULA: 